Demand planning estimates future customer demand so supply-chain teams can decide how much to order, produce, or move. Its purpose is not accuracy in isolation: a useful forecast supports better decisions, less unnecessary inventory, more sales, lower costs, and, when supply is constrained, stronger preparation for competition. section 1.1 section 1.2
Start with the business decision. Ask what must be forecast, which teams will use it, and whether the forecast supports production, inventory deployment, or plant decisions. Those answers determine the appropriate material, geographic, and time aggregation, along with the planning horizon. section 1.2.1 section 5.0
A practical process combines five linked activities:
- Set the right aggregation level and forecast horizon for the decision being supported. section 1.2
- Collect relevant demand data, rather than treating constrained sales as demand; add demand-driver data when its value justifies the effort. section 14.4.1 section 16.2.3
- Monitor forecasts with relevant metrics so performance can be assessed rather than assumed. section 1.2
- Use appropriate models to establish a forecast baseline. section 1.2
- Run an efficient review process that enriches the baseline without obscuring who added or reduced value. section 1.2 section 12.2.1
Match the forecast to inventory deployment
A monthly forecast by market may be poorly aligned when inventory is deployed weekly from plants to a small set of warehouses. Forecasting weekly by warehouse can avoid downstream flat splits that weaken an otherwise improved forecast. section 14.4.1
Treat the process as a sequence of contributions, not a single final number. Forecast Value Added compares each step—such as model, demand planner, sales team, and consensus—with the preceding step. This makes added accuracy, bias, ownership, and accountability visible, and can reveal edits that do not improve the forecast. section 12.2.1
Guard against bias in both information and governance. One-sided assumptions, missing lost-sales data, selective stakeholder input, or uneven demands to justify upward and downward adjustments can systematically distort the result. Review what evidence enters the process and whose judgment carries influence. section 16.2.3
Figure 1.2 5-step framework for demand planning excellence
Use the five-step framework as a planning map: define the forecast’s decision purpose, then align aggregation, data, metrics, models, and review. section 1.2
